Police in northern India said on Sunday that they had detained 15 suspects after a woman and her 14-year-old daughter were gang-raped off a busy highway, the latest incident of sexual violence to shock the country.

The attack took place on Friday night near the town of Bulandshahr in Uttar Pradesh state after the car in which the victims were travelling was stopped by a gang of men with an iron rod, said senior local police official Daljeet Choudhary.

The men dragged the woman, the daughter and three male relatives who were travelling with them to a nearby field. They then tied up the males and raped the woman and the daughter, Choudhary said.

He said several police teams were at work to ensure that the attackers were identified quickly. He gave no details about the detained men.

The family was also robbed of money, jewellery and their mobile phones.

The attack, which caused outrage across India, highlights the persistence of violence against women in the country despite tougher laws against sexual assault that were imposed following the December 2012 death of a young woman who was gang-raped on a bus in New Delhi.

After Friday's attack, opposition politicians in Uttar Pradesh accused the state government of failing to protect women and children.

Akhilesh Yadav, the chief minister of the state, asked local police to ensure that the attackers are identified and arrested quickly.